I only wear a shell jacket over whatever layers I need for the conditions... the Showers Pass jackets fill this role wonderfully as they are waterproof, windproof, and have a fairly good degree of breath-ability.

My wife owns 2 of them, she has one for summer and a larger one for winter to allow for more sweater space and her first SP jacket must be going on 6 or 7 years.

I use a Columbia Omnitech which is also great and is a longer jacket that is not cycling specific but fills me needs wonderfully on and off the bike.